Recent studies have demonstrated the effectiveness of hand held ultrasound imaging in detecting breast cancer, particularly for women with dense breasts. The latest reports have shown the potential to screen for small breast masses otherwise missed by mammography with up to 4.5 extra cancers detected per 1000 screens. A striking aspect of the added detections is that they are predominantly node negative invasive cancers which would have progressed to a later stage before possible mammographic detection. Despite these successes, handheld ultrasound is unlikely to be adopted for screening because it is operator-dependent, and its imaging aperture is small, which hinders whole breast imaging. To that end, automated breast ultrasound (ABUS) has been introduced as a way of overcoming these issues, mainly by reducing operator dependence and increasing the field of view. Unfortunately adoption of ultrasound screening has been slow. One major reason is that ABUS screening increases call back rates (up to a factor of 2 in case of the SomoInsight study). With its basic B-mode capability, it is unlikely that ABUS will be widely adopted for primary screening in the foreseeable future without more tissue-specific imaging capability. Improved lesion characterization would help lower the barriers to adoption of screening ultrasound. Our recently completed Fast Track grant demonstrated improved lesion characterization through tissue specific imaging in a diagnostic setting. These results suggest that improved specificity may therefore be realized in a screening setting, paving the way for screening trials as a natural extension of the activities under the parent grant. The objective of this study, therefore, is to characterize SoftVue's screening performance in the general population of women with dense breasts. The central hypothesis is that the area under the Receiver Operating Characteristic (ROC) curve is increased when digital mammography and SoftVue are used together versus mammography alone. The hypothesis will be tested by carrying out a multi-center clinical trial of 10,000 asymptomatic women having breast density categories of c and d. The trial will consist of a data collection phase at 6 sites across the US, followed by a pivotal reader study utilizing > 20 readers. The expected outcome of the study is an increase in the detection of invasive cancers compared to mammography and a reduction in call back rates compared to current ultrasound. The rationale for the proposed study is that a successful trial outcome will lead to FDA per-Market Approval which would enable Delphinus to market SoftVue for supplemental screening. The following specific aims will guide our study.